A jury in Florida recently acquitted a defendant after the judge refused to tell them what punishment he would face if convicted.
But why does a jury need to know what punishment the convicted will receive? After all, that fact is irrelevant to the question of whether the defendant actually committed the crime.
One answer is that juries should pass judgment not only on matters of fact, but also on matters of justice. Since the punishment could be out of proportion to the crime, jurors need to know the magnitude of the punishment to fulfill their duty. This is the jury nullification position – one that I generally agree with, but that is sadly out of fashion in our legal system. Jurors who confess an unwillingness to apply the law as stated by the judge are routinely dismissed during voir dire.
Setting aside jury nullification, I’ll suggest another reason that juries ought to know the likely punishment: From an efficiency standpoint, the standard of proof ought to be a function of the size of punishment.
In the current system, we have two main standards of proof: reasonable doubt in criminal cases, preponderance of the evidence in civil. (Yes, I realize there are others, such as "clear and convincing evidence," but they are much rarer.) What justifies the difference? David Friedman, in his book Law’s Order, argues that it’s related to the nature of the penalties. In civil cases, the penalty is usually a transfer of money, with no net loss to society other than the expense of enforcing the transfer. In criminal cases, the penalty is often jail time or worse, which imposes a cost on both the convicted person and the taxpaying public. As Friedman puts it, “Punishment [in criminal cases] is mostly net cost rather than transfer, so it makes sense to be a good deal more careful about imposing it.”
But in that case, why have only two commonly-used standards of proof? In general, the greater is the penalty, the greater is the cost to society of imposing it, which means we should be more careful about imposing larger criminal sanctions. It’s therefore economically sensible for jurors to regard reasonable doubt as a flexible standard – weaker when the punishment is small, stronger when the punishment is large. But they cannot accomplish the appropriate adjustment to the standard of proof when they lack the relevant information about the punishment.